A cassette of the above type is known from DE-PS No. 30 40 819 in which the use of a film-indicator device according to DE-PS No. 28 38 058 is proposed. See also DE-GM No. 7 928 371, DE No. 2856703, and DRP No. 825,947. In accordance with DE-PS No. 30 40 819 the film-indicator device is arranged in the upper portion of the cassette, which comprises the exposure window. However, owing to the limited space available the upper portion which forms a frame around the exposure window is unsuitable for the arrangement of such a film-indicator device because the light-shielding slider is guided, the sheet film pressed onto its support, and the light-protecting, labryrinth located, in this area. The other prior art has similar shortcomings.